TypeError ao tentar usar o tile de Citação

[hvelarde]

Ao tentar utilizar o tile de Citação acontece o seguinte erro:

2018-09-03T15:33:37 ERROR Zope.SiteErrorLog 1535999617.640.548445370565 http://example.org/pagina-inicia
l/@@updatetilecontent
Traceback (innermost last):
  Module ZPublisher.Publish, line 138, in publish
  Module ZPublisher.mapply, line 77, in mapply
  Module ZPublisher.Publish, line 48, in call_object
  Module collective.cover.browser.compose, line 64, in __call__
  Module collective.cover.browser.compose, line 56, in render
  Module plone.tiles.esi, line 87, in __call__
  Module Products.Five.browser.pagetemplatefile, line 125, in __call__
  Module Products.Five.browser.pagetemplatefile, line 59, in __call__
  Module zope.pagetemplate.pagetemplate, line 132, in pt_render
  Module five.pt.engine, line 98, in __call__
  Module z3c.pt.pagetemplate, line 163, in render
  Module chameleon.zpt.template, line 261, in render
  Module chameleon.template, line 191, in render
  Module chameleon.template, line 171, in render
  Module 5b8d590e7522d1d3e25b9292ecb3a92b, line 184, in render
  Module five.pt.expressions, line 161, in __call__
  Module brasil.gov.tiles.tiles.quote, line 74, in color_class
TypeError: cannot concatenate 'str' and 'NoneType' objects

 - Expression: "string:brasil-quote-tile tile-content ${view/color_class}"
 - Filename:   ... .gov.tiles/src/brasil/gov/tiles/tiles/templates/quote.pt
 - Location:   (line 14: col 29)
 - Source:     ... s string:brasil-quote-tile tile-content ${view/color_class}" ...
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 - Arguments:  repeat: {...} (0)
               template: <ViewPageTemplateFile - at 0x7fd528496350>
               views: <ViewMapper - at 0x7fd5280b2e50>
               modules: <instance - at 0x7fd53a2b4098>
               args: <tuple - at 0x7fd541aa7050>
               here: <ImplicitAcquisitionWrapper pagina-inicial at 0x7fd53166ab90>
               is_empty: <instancemethod is_empty at 0x7fd52ba4e8c0>
               user: <ImplicitAcquisitionWrapper - at 0x7fd53166a7d0>
               nothing: <NoneType - at 0x564e0ff64560>
               container: <ImplicitAcquisitionWrapper pagina-inicial at 0x7fd53166ab90>
               request: <instance - at 0x7fd528855200>
               wrapped_repeat: <SafeMapping - at 0x7fd5233fae68>
               traverse_subpath: <list - at 0x7fd5280c24d0>
               default: <object - at 0x7fd5419c2560>
               loop: {...} (0)
               context: <ImplicitAcquisitionWrapper pagina-inicial at 0x7fd53166ab90>
               view: <QuoteTile brasil.gov.tiles.quote at 0x7fd5280de850>
               translate: <function translate at 0x7fd5236dd488>
               root: <ImplicitAcquisitionWrapper Zope at 0x7fd529124370>
               options: {...} (0)
               target_language: pt_BR

[hvelarde]

corrigido em 40b81a4.